Evaluation of the Role of Ellagic Acid on Spatial Memory Activity and Oxidative Responses in Pentylenetetrazole Chronic Epileptic Rat Model

Abstract

Background: Epilepsy is a chronic neurological condition characterised by recurrent unprovoked seizures which are due to abnormal, excessive or  synchronous neuronal activity in the brain. An imbalance between excitatory and inhibitory neurotransmission of the brain, as a result of a decrease in  GABAergic and/or an increase in glutamatergic transmission, plays a role in the generation of epilepsy. This study assessed the effect of ellagic acid in  pentyleneterazolekindled rats and its role in spatial memory.

Methods: Sixty (60) male wistar rats weighing between 200 – 300g were randomly divided into six groups with 10 rats each. Groups I – V administered  with 35mg/kg pentyleneterazole, while group VI received distilled water subcutaneously (s.c) on alternate days for forty days. One hour before  pentyleneterazole administration, group II, III and IV received 15, 30 and 60 mg/kg (i.p) ellagic acid respectively and group V received 30mg/kg  Phenobarbital (i.p) and were observed for seizure activity 30 minutes after the pentyleneterazole injection. When kindling was achieved, elevated plus  maze and Y-maze tests for spatial memory were done. After which the rats were anaesthetised and brain tissue were removed. The brain tissues were  homogenised, centrifuged and the supernatant assayed for oxidative stress biomarker, malondialdehyde, antioxidant enzymes, superoxide dismutase  and catalase activities.

Results: The result showed significant (p < 0.05) increase in glutamate and malondialdehyde in group I when compared to other  groups but reduction in Yaminobutyric acid. There was increase in learning and retention ability in group IV as compared to the group I control in the  elevated plus maze test, and higher Y-Maze % mean score when compared to group I control.

Conclusion: Ellagic acid improves spatial learning and  memory, protects against seizures through mitigating oxidative stress by increasing antioxidants capacities and lowering glutamate concentration.